When I first read about the Chappe telegraph, I assumed that it must have been a short lived, quixotic experiment in long distance communication.

In fact, it was a network of towers which spanned France, provided the fastest form of communication known at the time, and which was adopted in several other countries.

However, it was rapidly rendered obsolete by the invention and adoption of the electric telegraph, which was faster, more reliable and much more secure. In the cartoon, Martin only knows of one remaining tower. There are actually several left in existence (you can find them on Google), but they don’t form anything like a network.

The example of the Chappe telegraph makes me wonder what other ubiquitous aspects of national infrastructure will become obsolete in the future: perhaps petrol stations will be next.

For a good, brief exploration of the Chappe telegraph and its replacement by the electric telegraph, try James Gleick’s book, The Information.

Some theories of human behaviour, particularly economics, tend to assume that humans are fully rational, especially when dealing with subjects such as number, which we suppose to be logical and free of emotion.

Psychological research in recent decades has shown this to be a myth. Many aspects of our behaviour and judgement are driven by heuristics; rules of thumb which are built into our brains. Brains which, remember, for most of human existence were found in the heads of hunter gatherers living in small tribes.

One of the most simple demonstrations of the power of heuristics was established by two of the pioneers in the field, Amos Tversky and Daniel Kahneman. They set up an experiment in which subjects were given a random number between one and one hundred, picked by spinning a wheel, and then asked whether the percentage of African nations in the UN was higher or lower than that number. They were then asked what their estimate was of the actual percentage of African nations in the UN.

They found that, even though the test subjects knew that the first number was random, their second answer was influenced by the first. (In fact, the first number wasn’t random: the wheel was rigged to give only two answers, 10 or 65.)

Further experiments found that this phenomenon applied to other situations, and even worked when the first number was from a completely different context: put on the spot to come up with a number, we will anchor our estimate on a number we heard recently, even if it is entirely irrelevant.

In his book Making Up The Mind, Chris Frith cites research in which experimental subjects are asked to play Tetris for several hours and then report on their dreams. They often report dreams of floating Tetris like blocks. Anyone who has played computer games or stared at spreadsheets for many hours a day will have had a similar experience.

The interesting thing is that even people who have lost the ability to form new memories report the same experience. These are people who suffer from the tragic condition of forgetting everything shortly after they experience it. You can introduce yourself to them every day and they will always think that they have never met you before. But they will dream of Tetris even though they may say that they have never heard of the game.

This is interesting because it reminds us that, as neuroscience increasingly shows, much of what goes on in our brains is not directly accessible to our consciousness and, even if it accessible, it is not necessarily under our conscious control.

Such knowledge is both fascinating, because it reveals ourselves to ourselves, and disconcerting, because it shows once again that we are the sum of our physical brains.